We’ve been able to reproduce the behavior you’re mentioning. The behavior you are experiencing could be caused by a timing issue during the composition in your application. According to the error messages provided, it looks like the
IModuleManager Import can’t be satisfied until the
IModuleInitializer composable part has been composed.

One possible workaround for this could be to use the ServiceLocator to resolve an instance of
IModuleManager, after your exported component has been fully loaded in order to avoid this unexpected behavior (for example, in reaction to a button in a component of yours).

On the other hand, if you think this timing issue is not desire, you can create an issue in the
Issue Tracker.